134 



OPERATIONS OF TILLAGE. 



way between them. This method of ploughing, it will 

 appear, has the same effect as turning the horses right 

 about, and is the most frequent and convenient in prac- 

 tice. 



" In the following figure, 22, in which C C, C C, C C 

 are the centres of the ridges, the manner in which the 

 successive furrow-slices have been laid upon each other 

 is shown. 



Fig. 22. 



" By this laying of the earth towards the centres, the 

 ridges acquire a certain curvature. By ploughing the 

 earth away from the intervals D E, F G, the ground is 

 hollowed at these parts, which now forms the open furrows. 

 It is by these open furrows that the water which falls 

 upon the surface finds a passage. 



" A certain, though not a great, degree of curvature, 

 is given to the ridge by this ploughing. It is frequently, 

 however, necessary to give it a yet greater degree of cur- 

 vature and elevation. This is done by ploughing the 

 whole ridge a second time, and in a similar manner. 



*' The plough is first driven along the centre of the 

 ridge from C to C, forming an open furrow. Successive 

 furrow-slices are then laid towards this furrow, in the 

 same manner as in the previous ploughing. This is done 



